Preparation of cyclododecanol

ABSTRACT

A process for the preparation of a cyclic alcohol by air oxidation of a cycloaliphatic compound to a mixture containing 130 percent by weight cycloaliphatic hydroperoxide, oxidizing cycloolefin by means of the cycloaliphatic hydroperoxide, hydrogenating the resulting product, and recovering cyclic alcohol and unconverted cycloaliphatic compound for recycle.

United States Patent [72] Inven r Donald Eldon welmll 2,855,437 10/1958 Lyons.... 260/610 A Victoria, 2,997,483 8/1961 Gray 260/617 M [21] App1.No. 706,018 3,238,238 3/1966 McNamara et a1. 260/617 M [22] Filed F 1 1968 3,333,010 7/1967 Urbanek 260/617 M [45] Patented Sept. 21, 1971 3,351,635 11/1967 K011ar 260/617 [73] Assignee E. I. du Pont de Nemours and Company 3,391,213 7/1968 Fetterly. 260/632 CP Wilmington, Del. 3,391,214 7/1968 Fetterly 260/632 C 3,467,720 9/1969 List et a1. 260/632 C [54] PREPARATION OF CYCLODODECANOL FORElGN }?A:TENTS 8 Claims, 1 Drawing 918,444 2/1963 Great Brltaln 260/617 M 52 us. c1 260/617 c, Primary Ziwe 23/139, 252/467, 260/349.5 L, 260/531 R Assistant Exammer-Joseph E. Evans 260/586 A, 260/610 B, 260/666 P Ammey Handle) [51 I Int. Cl ..C07c 35/02, C07c 51/28 [50] Field of Search 260/617 M, ABSTRACT: A process for the preparation ofa cyclic alcohol 632 C, 632 CB,610 B, 617 R by air oxidation of a cycloaliphatic compound to a mixture containing 1-30 percent by weight cycloaliphatic hydroperox- [56] References cued ide, oxidizing cycloolefin by means of the cycloaliphatic UNITED STATES PATENTS hydroperoxide, hydrogenating the resulting product, and 2,615,921 10 1952 Dougherty et a1. 260/632 0 recovering cyclic alcohol and unconverted cycloaliphatic 2,671,119 3/1954 Mertzweiller 260/638 compound for y A111 GYOLODODEOATRIENE CATALYST 11 REGYCLE A111 T T i i CA MYS CYCLODODEOANE mum: PEROXIDE Maw & HYDROGEN L RECYCLE RECYCLE PRODUCT I CYCLODODECANOL i i l.

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INVENTOR DONALD E. WELTON ATTORNEY PREPARATION OF CYCLODODECANOL This invention relates to a process for the production of cycloaliphatic alcohols from cycloaliphatic compounds and cycloolefins.

It is known to air oxidize cyclododecane to a mixture containing cyclododecanol. The mixture also usually contains other oxidative products, such as cyclododecanone and cyclododecyl hydroperoxide. Such air oxidation systems often include boric acid or another boron compound-see British Pat. No. 1,032,390 to E. I. du Pont de Nemours and Company and British Pat NO. 1,064,167 to Esso Research & Engineering Company.

A convenient source of cyclododecane is the trimerization of butadiene, followed by hydrogenation of this product. A convenient source of cyclooctane is dimerization of-butadiene followed by hydrogenation of this product.

The present invention is based on the discovery that the product of any air oxidation system of cyclododecane which contains 1 to 30 percent cyclododecyl hydroperoxide can be used as a source of oxygen to convert cyclododecatriene to intermediates, cyclododecatriene oxides, that upon hydrogenation gives cyclododecanol in high yields with only a small amount of byproduct. The cyclododecyl hydroperoxide is reduced upon reaction with the cyclododecatriene and it also forms cyclododecanol. This ability of the cyclododecyl hydroperoxide to oxidize cyclododecatriene is employed in the overall process as follows: cyclododecane is air oxidized to a mixture containing 1 to 30 percent cyclododecyl hydroperozide. This mixture will also contain small amounts of cyclododecanol, cyclododecanone, and other oxidative products. The cyclododecanol does not chemically react in the remaining steps. Cyclododecatriene is then added to this mixture in more than stoichiometric amounts, based upon the amount of hydroperoxide present, usually in the amount of 1.1 to three times the amount of hydroperoxide present, and the cyclododecatriene oxidized, forming oxygenated, olefinic intermediates. The mixture is then hydrogenated and the intermediates, cyclododecatriene oxides, are converted to cyclododecanol. The unreacted cyclododecatriene which was added in an excess amount is hydrogenated to cyclododecane. The hydrogenation reaction also reduces the cyclododecanone to cyclododecanol. The cyclododecanol is then recovered, for example, by distillation and the cyclododecane is recycled to the air oxidation step.

The air oxidation of cyclododecane to a mixture containing cyclododecyl hydroperoxide may be carried out by any of the several processes known in the art, either with or without a modifier such as boric acid. The preferred conditions are those which maximize hydroperoxide formation. Suitable conditions for bubbling air though cyclododecane are l40l70 C., preferably as close to 140 C. as possible, and at atmospheric pressure. Ozone may be added to the air to allow use of lower temperatures.

The mixture containing the cyclododecyl hydroperoxide is then reacted with cyclododecatriene. This latter reaction is preferably carried our at a temperature in the range of about 60 C. to about 140 C. as below this temperature the mixture is solid, and above this temperature the reaction goes with low yield, preferably at 80 C. to 120 C.; a catalyst is also preferably present. Suitable catalysts include boric acid compounds such as orthoboric acid, boric oxide, borate esters, i.e. trimethyl borate, triethyl borate, vanadium compounds, such as vanadium pentoxide, borovanadic acids, and oxides; molybdenum compounds such as molybdic anhydride, molybdic acid, boromolybdic acids, peroxymolybdic acid, molybdenum blue, molybdous oxide, and mixtures of these materials. When the catalyst is boric acid, or a derivative, the amount added will be in the range of about 0.5 to 5 mol per mol of cyclododecyl hydroperoxide present. When the catalyst is one of the others mentioned, it will be about 0.005 percent .to 0.5 percent by weight of the total organics (cyclododecane,

cyclododecanol, cyclododecanone, cyclododecyl hydroperoxide, and other oxidation products and the added cyclododecatriene) present. The pressure of the reaction is not critical, and may vary from about 20 Torr to one or two atmospheres absolute.

The hydrogenation of the mixture containing the intermediates is carried out using conventional hydrogenation techniques, such as a fixed bed catalyst of nickel oxide, nickel on Kieselguhr or alumina, supported platinum, and palladium black; Raney nickel, cobalt molybdate, or nickel tungsten sulfide. Such reactions are conventionally carried out at C. to 250 C., and at pressures of 40 to 5000 p.s;i., preferably 50 to 500 p.s.i., the particular conditions being selected so as to substantially completely saturate theolefinic unsaturation and to reduce ketone to alcohol.

The attached schematic drawing further illustrates the process. Cyclododecane and air are fed into an air oxidizer reactor 1, wherein the cyclododecane is oxidized to a product containing cyclododecyl hydroperoxide. This product is fed to peroxide reactor 2 where it is mixed and reacted with cyclododecatriene in the presence of added catalyst. The reaction mixture is then fed to catalyst removal and neutralizer where it is suitably treated to remove the catalyst and neutralizeany organic acids formed by the oxidation steps, and any acidic catalyst residues that are present. The particular catalyst removal step carried out will depend on the catalyst employed. lf boric acid is the catalyst, mere water wash at a temperature above about 60 C. will remove a majority of the catalyst; the remainder is neutralized by the subsequent addition of mild alkali solution-pH of 8-12. The boric acid is then dehydrated and recycled to the peroxide reactor. 1f the catalyst is not boric acid, but instead molybdic oxide or the like, the catalyst may be removed by a water wash that contains small amounts of alkalipH of 8-l2 at contact times of 1-30 minutes at temperatures of 60-1 10 C. Such catalysts may be discarded or purified and recycled.

The reaction mixture is then passed into hydrogen reactor 4, where in the presence of a hydrogenation catalyst most of the cyclododecatriene oxides and cyclododecanone are reduced to cyclododecanol, and cyclododecatriene which was added in excess in the peroxide reaction is reduced 'to cyclododecane. The reaction mass is then passed to the cyclododecane recovery still 5, where cyclododecane is recovered and recycled to the air oxidation step. The remaining portion of the reaction mass is then passed to the unhydrogenated product recovery still 6, where products that were not fully reduced to cyclododecane or cyclododecanol are removed and recycled to the hydrogenation reactor 4. Finally, the reaction mass is passed into the cyclododecanol refining still 7, where this product is removed from the high boiling organics formed in the previous reactions.

It is possible to modify the reaction scheme in various ways, for example, more than one hydrogen reactor 4 could be employed or long holdup times employed in a single reactor 4, thus eliminating the need for an unhydrogenated product recovery still 6.

In the following examples which illustrate the invention all parts and percentages are in parts by weight unless otherwise specified.

EXAMPLE 1 cyclododecane was air oxidized in a conventional manner to form a mixture containing about 5.1 percent cyclododecyl hydroperoxide. 2.1 mols of cyclododecatriene and 1.8 mol of metaboric acid were added for each mol of hydroperoxide, and the mixture heated at C. for 1.75 hours. 99 percent of the hydroperoxide was reacted by the end of this time. 0.49 mol boric acid/mol of cyclododecyl hydroperoxide charged went into solution. The boric acid was removed by hydrolysis and extraction with hot water. Upon analysis of the product it was found that 0.85 mols of cyclododecatriene had been oxidized for each mol of cyclododecyl hydroperoxide present. The product was hydrogenated by adding 1 percent by weight palladium black catalyst, and pressured with hydrogen at 40 p.s.i. while it was agitated and heated to about 100 C. until the pressure remained constant. Analysis of the product showed that 95 percent of the oxidized cyclododecatriene was converted to cyclododecanol or products that on further hydrogenation would produce cyclododecanol; a total of 0.73 mol of these products was obtained for each mol of peroxide charged.

EXAMPLE 2 Cyclododecane was air oxidized to form a mixture containing 6.9 percent cyclododecyl hydroperoxide. Cyclododecatriene was added in the amount of 2.1 mols/mol of hydroperoxide, and about 500 ppm. permolybdic oxide catalyst was added and the temperature maintained at 100 C. for 1 hour. (The catalyst was prepared by suspending 1 part molybdic anhydride (M in 20 parts water and adding parts of a 30 percent solution of hydrogen peroxide. The solution was heated to 90-100 C. until a clear yellow solution was obtained, and then dried on a steam bath. The yellow solid analyzed, by iodometric analysis, 81 percent 11 M00 At the end of 1 hour the hydroperoxide was 98 percent reduced. The product was filtered. Analysis of the filtered product showed that 0.80 mol of cyclododecatriene per mol of cyclododecyl hydroperoxide was converted to products that on reduction would produce cyclododecanol. The product was washed with water containing a small amount of sodium hydroxide to remove the catalyst and neutralize the organic acids and catalyst residues.

The product was then mixed with about 2.5 percent by weight Raney nickel power and hydrogenated at 40-50 p.s.i.g. at 100 C. until absorption of hydrogen ceased. The hydrogen absorbed 100 percent of that calculated from analysis of the feed to be necessary to convert all unreacted cyclododecatriene to cyclododecane and all the oxygenated product to cyclododecanol. The catalyst was removed by filtration and the product analyzed. It contained 10.5 weight percent cyclododecanol, 0.27 weight percent cyclododecanone, and 0.04 percent cyclododecyl epoxide.

The product was subjected to vacuum distillation and separated into four fractions to give 99.1 weight percent recovery. (1) A fraction was removed at l04l05 C. at a pressure of torr. This fraction contained about 86.8 percent of the charged product, and contained mostly cyclododecane with about 0.3 weight percent cyclododecanol and cyclododecanone. This fraction may be recycled to the air oxidation step. (2) The pressure was then reduced to about 6 torr and a fraction removed having a boiling point of 97132 C. This fraction contained about 3.5 weight percent of the charged product. This fraction contained about 54 weight percent cyclododecanol, 5.1 weight percent cyclododecanone, 0.4 weight percent cyclododecane epoxide and 43.4 weight percent cyclododecane. This fraction may be recycled to the hydrogenation step to convert the cyclododecane epoxide and cyclododecanone to cyclododecanol. (3) The temperature was then increased while maintaining the pressure at about 6 torr and a fraction containing about 8.0 weight percent of the charged product was recovered. This fraction contained greater than 96 weight percent cyclododecanol, 0.3 weight percent cyclododecane epoxide, 1.0 weight percent cyclododecanone and 2.5 weight percent cyclododecane. This product is of sufficiently high purity to be used in this form, but further distillation to further purify the product can be carried out. (4) A high boiling residue containing about 0.88 weight percent of the charge remained. This fraction contained about 5 weight percent cyclododecanol.

The process illustrated by this invention can also be employed to make alcohols of other cyclic olefins, for example, the butadiene cyclic dimer could be used for the alcohol, which by further oxidation will produce octane dioic acid.

1 claim:

1. A process for the preparation of cyclododecanol which comprises the steps of l air oxidizing cyclododecane to form a mixture containing cyclododecane cyclododecanone, and

1 percent to 30 percent by weight cyclododecyl hydroperoxide, by bubbling air through cyclododecane at C. to C., (2) oxidizing cyclododecatriene by reacting it with said mixture in the presence of a catalyst selected from the class consisting of orthoboric acid, boric oxide, trimethyl borate, triethyl borate, vanadium pentoxide, borovanadic acid, vanadium oxide, molybdic anhydrode, molybdic acid, boromolybdic acid, peroxymolybdic acid, molybdenum blue, and molybdous oxide at a temperature of 60 C. to 140 C., the mol ratio to cyclododecatriene to cyclododecyl hydroperoxide being about 1.5 to 3, to form a mixture containing cyclododecatriene oxides, (3) hydrogenating this mixture using a hydrogenation catalyst selected from the class consisting of nickel oxide, nickel on Kieselguhr, nickel on alumina, supported platinum, palladium black, Raney nickel, cobalt molybdate, and nickel tungsten sulfide, at a temperature of 100 C.250 C. and at a pressure of 40 to 5,000 pounds per square inch, (4) recovering cyclododecanol from this hydrogenated product.

2. The process of claim 1 in which the catalyst used in the oxidizing of the cyclododecatriene is removed prior to hydrogenating the mixture containing cyclododecatriene oxides.

3. The process of claim 2 in which the cyclododecane is recovered from the hydrogenated product and recycled to the air oxidation step.

4. The process of claim 3 in which a mixture containing cyclododecanone and cyclododecane epoxide is recovered from the hydrogenated product and recycled to the hydrogenation step.

5. The process of claim 4 in which the air oxidized product is neutralized by washing with dilute aqueous alkali prior to hydrogenation of the air oxidized product.

6. The process of claim 1 in which the catalyst employed in the oxidation of cyclododecatriene is orthoboric acid, and said catalyst is present in the amount of 0.5 to 5 mol per mol of cyclododecyl hydroperoxide present.

7. The process of claim 1 in which the catalyst employed in the oxidation of cyclododecatriene is a molybdenum containing catalyst and said catalyst is present in the amount of 0.005 to 0.5 percent by weight of the total organics present.

8. The process of claim 1 in which the catalyst employed in the oxidation of cyclododecatriene is a vanadium containing catalyst and said catalyst is present in the amount of 0.005 to 0.5 percent by weight of the total organics present. 

2. The process of claim 1 in which the catalyst used in the oxidizing of the cyclododecatriene is removed prior to hydrogenating the mixture containing cyclododecatriene oxides.
 3. The process of claim 2 in which the cyclododecane is recovered from the hydrogenated product and recycled to the air oxidation step.
 4. The process of claim 3 in which a mixture containing cyclododecanone and cyclododecane epoxide is recovered from the hydrogenated product and recycled to the hydrogenation step.
 5. The process of claim 4 in which the air oxidized product is neutralized by washing with dilute aqueous alkali prior to hydrogenation of the air oxiDized product.
 6. The process of claim 1 in which the catalyst employed in the oxidation of cyclododecatriene is orthoboric acid, and said catalyst is present in the amount of 0.5 to 5 mol per mol of cyclododecyl hydroperoxide present.
 7. The process of claim 1 in which the catalyst employed in the oxidation of cyclododecatriene is a molybdenum containing catalyst and said catalyst is present in the amount of 0.005 to 0.5 percent by weight of the total organics present.
 8. The process of claim 1 in which the catalyst employed in the oxidation of cyclododecatriene is a vanadium containing catalyst and said catalyst is present in the amount of 0.005 to 0.5 percent by weight of the total organics present. 